| 摘要 |
A differential and absolute transducer are secured to a Pyrex glass header by means of a glass metal frit or other suitable interface. One of the sensors measures absolute pressure and the sensor is a sealed cavity, while the other sensor is designed to measure differential pressure and the sensor is an aperture which permits the pressure media to reach both sides of the sensor. The header itself has a through hole connected to a tube over which the differential sensor is affixed. The Pyrex glass is chosen to match the coefficient expansion of the sensors. The header in turn is attached to the tubular member provided with a fitting such that static pressure can be applied to both sensors simultaneously. At the other end of the tubular member, there is provided another fitting attached to the tube in the header through which the total pressure can be applied to the differential sensor, thus permitting the measurement of the difference between the total pressure and the static pressure. Each of the sensors is fabricated by the same processing techniques and is of the same thickness, but have different deflecting areas such that the differential sensor will have a greater stress through the same pressure. By obtaining both the differential and the static pressure, one can now determine air speed by the solution of several derived equation for speed in both a compressible and an incompressible flow, such as through air or any other fluid.
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